The present invention relates to containers for the spray dispensing of liquid, having a spray nozzle arranged on the top of the container and a handle for a pump which is associated with the container and has a pump cylinder, piston rod and pump piston for producing a cushion of compressed air above the surface of the liquid.
Dispensers of this type are extensively replacing spray devices which operate with propulsion agents which are environmentally objectionable. One device of this type is known, for instance, from U.S. Pat. No. 3,955,720, FIG. 12. The pump handle of the can be locked on the container in the basic position. The top or head surface of the container is provided for this purpose with a constriction having a detent groove developed on its inner side. The plate-shaped edge of the handle engages into said groove. In this way, any residual pressure remaining in the pump is prevented from lifting the pump handle out of the basic position and into an undefinable protruding position. Since the handle can pass into this locked position upon normal actuation of the pump already at the full stroke, this measure, however, proves troublesome since the handle must then be pulled out again with difficulty at a tubular connectorpiece which extends outward beyond the plate. All this impairs the operation of such propellant-free containers or dispensers. Furthermore, the action of heat can lead to such conditions of expansion that the internal pressure overcomes said detent means, resulting in creeping out and even in a protrusion which lifts off the protective cover. Accidental contact with articles contained in a bag can result unfavorably in the undesired release of the spray device. The passage of air into the inside of the container takes place furthermore at the bottom of the pump which extends from the top into the container. Depending on the level of filling, the air is forced through the liquid. This, as a rule, causes a gurgling noise. There is furthermore the disadvantage that, with the passage of time, liquid leaks outward over the air-feed path. This not only constitutes a loss but also decreases the acceptance of such dispensers.
The object of the present invention is to develop a dispenser of this type in a manner which is more favorable from the standpoint of use and handling while avoiding the abovementioned disadvantage of the springing back of the piston.